GB-A-2 120 475 describes a way of strengthening a particulate matrix in which relatively small, light weight, generally flat pieces of flexible, open plastics mesh structure are randomly embedded in the matrix. GB-A-2 120 475 can be referred to for details. Such pieces each weigh less than 5 g, and have a weight of less than 80 g/m.sup.2 or more particularly less than 50 g/m.sup.2.
The normal way of embedding the mesh pieces in the matrix is to mix them together. The supply of the mesh pieces to the point of mixing has given significant problems. In GB-A-2 120 475, it is suggested that a continuous length of mesh can be cut up into the pieces immediately before mixing, but in practice, this is not convenient. End-users wish to buy the mesh pieces already cut. This requires that the mesh pieces should be packaged so that they occupy a relatively small space, and the mesh pieces must be flat and relatively easy to disentagle from each other.
The high flexural recovery of the mesh pieces makes them very difficult to package in a dense form. Attempts have been made to stack the pieces and then ram them so that they can be wrapped with film in a compact bale.
It was not found possible to stack the mesh pieces without creasing, and the mesh pieces became very tightly interlocked after compression and were difficult to separate by the end user.
The size and weight of each individual mesh piece is so small that it is very easily moved by vibration, air flow, static electricity or contact with moving parts, so that there are immense difficulties in providing any ordered arrangement. Furthermore, because the mesh pieces are flat and severed from the same sheet of mesh material, they are very close to each other, and a minimum of movement of any mesh piece will cause interlocking with its neighbour and a chain reaction with other mesh pieces. If this happens, it is nearly impossible to handle the mesh pieces. Because of the way in which the mesh pieces are slit, each piece will have protruding strands around its edges, which easily engage the protruding strands of the next mesh piece, or indeed lock into the meshes of the next mesh piece.